Joining two queries together

[sdollen]

I created a contact database where I track contacts based on visits to a customer and seeing a customer at a conference in two tables (visit and conference).

I ran two queries for both tables against a customer name table and pulled the unmatched on the visit and conference tables.

This gives me two queries which shows me who hasn't had a visit or hasn't been to a conference.

Make sense so far? And, yes I'm sure my table structure isn't the best

Now, how can I do a union between the two queries so I can see who hasn't had a visit AND hasn't been to a conference?

Thank you for any help. This is truly a GREAT forum.

 

[sdollen]

Hmm.... I was sitting here thinking about my post..and actually, I don't need to know who hasn't had a visit AND who hasn't been to a conference.

I need to figure out how hasn't had a visit OR who hasn't been to a conference.

That would still be the union of the two queries though.. wouldn't it? It's late in the day to think

-Stefan

 

[r937]

yes, you could do it with a union

select username
  from usertable
 where not exists
       ( select 1 
           from visits
          where visits.userid = usertable.userid )
union
select username
  from usertable
 where not exists
       ( select 1 
           from confs
          where confs.userid = usertable.userid )

on the other hand, you can do it in one query too, just put those two conditions into one WHERE clause -- then you could also decide whether you wanted AND or OR

rudy